What's better, one conductor or two conductors for an RCA interconnect?

Furtwangler and Toscanini?

I did a experiment once.

I tried to measure if I could get any graph or see any benefits or difference between my trippel shielded (stated on the jacket) RCA and new bought but braided sterling silver RCA.

I wanted to see if there were ANY notable diffrence between them and I don't want to make things worse down the road and note that X hours later.

I measured with the calibrated microphone and REW with the mic on stand. Then I switched out the triple one to the silver one and redo the measurements again with no other changes at all.

I sat down and compared the two measurements back and forth and really tried to find a difference somewhere/anywhere. I went through all 10-15 different types of graphs that I could find in REW and analyzed them and comparing them back and forth. That could give me any clue on what could be changed between differens shielded/braided or copper/silver.

I did not find anything at all only in one graph for impulse response that the silver had MAYBE a little bit better in that graph.

But it's so small that probably needed to run 10 measurements on each cable and analyze those and see if there were any average measurements difference. Now with only one measument of each RCA the difference could be normal variation between measurements that i had noticed. Yes ot were not a big difference!

With all that said i just let the new silver cable be in the system when it anyway didn't had any negative effects.

Another conclusion as far as cable construction, crossection and geometry when they were totally different is that it didn't do any difference in this situation*.

*Situation = if you have alot of RF in your place (near a radio station) or if you have low signal level as from TT to RIAA. That is a total different situations. And why some have totally different experiences.

But I see higher end RCA cables with two conductors and ground wire.

@jumia Can you show an example of such cable?

I’ll second what @kijanki wrote. I have never encountered RCA connectors used with coaxial cables. I would expect coaxial cables to use BNC connectors, as I think someone else mentioned. The higher end cables, such as those that came from the factory with my Musical Fidelity turntable, are marked with a directional arrow, which I’m assuming points in the direction of the signal. It also denotes, for me, that the shield is only connected at the phono stage, not the turntable. The turntable does not have a three-conductor line plug 🔌 (which is a good thing to me), it uses a wall wart.

The other thing to consider when selecting cables (aside from whether or not it is shielded), is its impedance rating in Ohms. Cables using the same connectors have different impedance ratings for use in either analog or digital applications. I can’t recall the values off the top of my head, but they will each ‘work’ in place of the other, but the energy transfer is not optimal and shouldn’t be considered for permanent installation. The same distinction holds true for XLR connectors; analog applications (I.e. ‘balanced’ connections) cables have impedance ratings which are different than those cables used in digital cables (I.e. AES/EBU connections).

More experienced or knowledgeable members are free to correct or explain further the reasons for the difference I describe.

If you’re purchasing cables, I would avoid coaxial cables using RCA connectors, if you are contemplating making your own, I would buy at least two-conductor shielded cable (I like Mogami), and consider using four conductor cable (twisted pair) together with the best connectors you can find. I have found good prices and fast delivery from B & H Photo, but would probably consider using one of the specialized cable companies mentioned on this forum the next go-round.

Hope this helps

Blue Jeans Cable recommends coaxial cables for subwoofer, stereo audio, digital audio, etc.  They state that, “The most important attributes of a line-level unbalanced audio cable are (1) shielding, and (2) capacitance. Heavy shielding protects audio signals from interference from outside sources. LC-1 Audio Cable uses a heavy double-braid shield, with one bare copper braid laid directly over another for extreme high coverage and high conductivity to ground; this is the identical shield configuration to Canare LV-77S, which tested best in our review of audio cable hum rejection characteristics (LC-1 hadn't been designed yet so wasn't tested at that time). By shrinking the center conductor to 25 AWG and foaming the polyethylene dielectric, we were able to get capacitance down to an extremely low 12.2 pF/ft, much better than LV-77S at 21 pF/ft. Capacitance can be important, particularly in long cable runs, because it contributes to rolloff of higher frequencies.”